I HAVE LOST MY PHONE SOMEWHERE IN MY HOUSE AND THE BATTERY IS DEAD. I HAVE MY OLD PHONE AND WANTED TO KNOW IF I SWITCH BACK TO IT IS THERE GOING TO BE A CHARGE FOR DOING SO AND IF I FIND MY OTHER PHONE AND SWITCH BACK TO IT WILL THERE BE AN ADDITIONAL CHARGE???
Since you are in the Basic Phones area I am assuming that the device you lost wasn't a smartphone, if the device isn't a smart device and you transfer to the Charge you will be required to change the data plan to a smartphone data plan which would most likely cost you addition fees.
As far as I know there is no charge to switch back to your old phone. Recently I switched to an old phone, and then switched to another phone and was not charged activation fee in either case. Both phones were compatible with my plan. If you are switching between phones that do require and don't require data that is a different story.